Question 1: Why do capacitors have polarity? Only capacitors will explode if connected in reverse. Other capacitors do not distinguish between positive and negative poles. Because electrolytic capacitors are connected in parallel to the positive and negative terminals of the power supply, other capacitors are connected in series in the line.
Question 2: There is polarity What is the difference between a capacitor and a non-polar capacitor? 30 points A polarized capacitor has positive and negative electrodes. The voltage between the positive and negative electrodes must be positive, otherwise the capacitor will be damaged
Common ones include aluminum electrolytic capacitors and tantalum Capacitor
Stepless capacitors have no positive and negative electrodes, and the voltage between the positive and negative electrodes can be positive or negative
Common ceramic capacitors
have two Each type of capacitor has a withstand voltage value. If it exceeds this value, the capacitor will be damaged.
There is no tutorial on repairing computers. Computers are very complicated things. Professionals cannot repair complex contents, but if If the capacitor is damaged, you can replace it yourself
Damage to aluminum electrolytic capacitors on computer motherboards is common. If there is a burst or the capacitor swells, you can replace it yourself. Pay attention to the fact that the capacitance and withstand voltage values ??are consistent.
Question 3: What are the polar capacitors? There are aluminum electrolytic capacitors (produced by different media and processes in various countries, and the quality varies), solid tantalum electrolytic capacitors (domestic ones with high quality and large output), Sanyo OS solid metal sintered electrolytic capacitors (Japanese Sanyo patented only two of its native countries in the world) Produced by several manufacturers), currently there are only three categories of polarized capacitors!
Question 4: As shown in the picture, what does it mean that a capacitor has polarity and non-polarity? To make it easier to understand, the literal understanding of polarity refers to the positive and negative polarities. Polarized capacitors must be connected to the circuit separately. Reverse connection may cause explosion (explosion). Most electrolytic capacitors are polarized, such as adapters. The filter capacitors inside, etc. and the solid capacitors on the computer motherboard are all polarized. Polarized capacitors generally have larger capacities
However, non-polar capacitors can be connected to pins regardless of the positive and negative poles. The positive electrode can also be connected to the negative electrode, such as ceramic capacitors, monolithic capacitors, polyester capacitors, etc. Non-polar capacitors generally have smaller capacities.
Question 5: Can non-polar capacitors replace ordinary polarized electrolytic capacitors? The ideal capacitor should be Non-polarized, such capacitors can be used in any AC or DC circuit.
Generally, as long as the capacity and withstand voltage are the same, non-polar capacitors can be used instead of electrolytic capacitors (the opposite is not necessarily true). Practical applications also need to consider differences in size, price, and other indicators of capacitance.
The reason why electrolytic capacitors are polarized is due to their manufacturing method. This manufacturing method can create capacitors with a large capacity/volume ratio, which is about ten times the highest value in other methods, but it is also It brings polarity, that is, it cannot be connected in reverse, and its use is limited. Electrolytic capacitors are mostly used in pulsating DC filtering or power supply decoupling, and this application is also quite common and important.
The competition between non-polar capacitors and electrolytic capacitors is fierce, but so far, electrolytic capacitors have not been driven out of the market. There are many reasons, such as noise, temperature coefficient, etc., but the most important one is High capacity/volume ratio of electrolytic capacitors, especially single large capacitors.
Question 6: Can non-polar capacitors replace polar capacitors? Non-polar capacitors can completely replace electrolytic capacitors, as long as you pay attention to the withstand voltage. Electrolytic capacitors rely on the oxide film of the aluminum foil to react with the electrolyte to store charge, similar to For batteries, the advantage is that it has a large capacity and is cheap, but you have to pay attention to the polarity, and it cannot be used for AC.
Question 7: 104 capacitors are not divided into polarities. If so, how should they be divided? Among the capacitors, there are ceramic capacitors and film capacitors with 104. There is no distinction between polarity. 104 is also called 100000PF with positive and negative poles. Be careful not to use 102 and 103 instead of passing through. There is a 10-fold difference between 103 and 104, but there is no distinction between polarity.
Question 8: What is the function of polar capacitors? The so-called capacitor is an electronic component that holds and releases electric charge. The basic working principle of a capacitor is charging and discharging, and of course it also has rectification, oscillation and other functions. In addition, the structure of the capacitor is very simple, mainly composed of two positive and negative electrodes and an insulating medium sandwiched in between, so the type of capacitor is mainly determined by the electrodes and the insulating medium.
Capacitors have many uses, the main ones are as follows:
1. DC blocking: The function is to prevent DC from passing through and allow AC to pass through.
2. Bypass (decoupling): Provides a low-impedance path for certain parallel components in an AC circuit.
3. Coupling: As a connection between two circuits, allowing AC signals to pass through and be transmitted to the next circuit
4. Filtering: This is very important for DIY. The capacitors on the graphics card basically have this function.
5． Temperature compensation: Compensate for the impact of other components' insufficient adaptability to temperature to improve the stability of the circuit.
6. Timing: Capacitors are used in conjunction with resistors to determine the time constant of a circuit.
7. Tuning: System tuning of frequency-dependent circuits, such as cell phones, radios, and televisions.
8. Rectification: Opening or closing a semi-closed conductor switching element at a predetermined time.
9． Energy storage: Stores electrical energy and releases it when necessary. Such as camera flash, heating equipment, etc. (Today, the energy storage level of some capacitors is close to that of lithium batteries. The energy stored by a capacitor can be used by a mobile phone for a day.
Question 9: Why do electrolytic capacitors have polarity? The capacity of a capacitor is related to The square of the distance between the two electrodes is inversely proportional to the area. The electrolytic capacitor uses an electrolytic (DC) process to form an oxide film on the surface of the aluminum foil. Because this oxide film is extremely thin, the capacity of the electrolytic capacitor can be very large. However, this electrolytic film has polarity. If the polarity of the capacitor is reversed, the electrolytic film will break down quickly and the capacitor will fail.
Question 10: Aluminum electrolytic capacitors have polarity. Why? The polarity of electrolytic capacitors can be analyzed from a chemical perspective. From a chemical valence perspective, the chemical valence conversion of aluminum trioxide is as follows
< p> So you should know why electrolytic capacitors are polarized!